This invention relates to an improved cassette for holding and applying reagents to a slide that bears samples to be assayed, and methods for use of the cassette.
An embodiment of the present invention relates to a system for holding a slide. The system includes a housing having a side wall and a top. The top includes a recess surrounded by an outer rim. The system also includes an inlet port in communication with the recess and an elevating mechanism capable of receiving the slide and for raising the slide toward the top of the housing to engage the slide with the outer rim to form an analytical cavity. Together these elements form an analytical cavity in which the assay may be performed.
Processing of biological samples on glass slides has a long history. Compared to the relatively simple dyes and stains of previous years, many newer techniques for analysis are significantly more complex and the reagents considerably more expensive. Immunoassays, hybridization assays, and in situ nucleic acid amplification assays are particularly demanding in terms of reagent expense, need for accurate timing, and need for precise temperature control. These are particularly demanding because the reagents should be applied in a precisely controlled thickness. Further, some of these assays involve heating of the slide and reagents to produce enzymatic reactions, yet the reagents must not evaporate during the procedure. In addition, it is desirable to have the assays performed automatically to whatever extent is possible, both to save cost and for increased reliability and precision.